Cut-out.



J. T. MARSHALL.

GUT-OUT. APPLIOATION FILED JUNE 26.1905.

14017765565: 194M 4 M er/tor.- l John TMaas/m.

UNITED STATES PATENT OFFICE.

JOHN T. MARSHALL, OF METUCHEN, NEW

JERSEY, ASSIGN OR TO GENERAL Specification of Letters Patent.

Patented May 28, 1907..

Application filed June 26, 1905. Serial No. 266,954.

To all whom it may concern:

'Be it known that 1, JOHN T. hilARSHALL, a citizen of the United States, residing at the borough. of Metuchen, county of Middlesex, State of New Jersey, have invented certain new and useful Improvements in Cut-Outs, of which the following is a specification.

The present invention relates to that class of circuit controlling devices commonly called cut-outs which depend upon the rupturing or breaking down of an insulating substance held between contact surfaces for the purpose of maintaining an electric circuit. Such devices are usually arranged in shunt to a translating device such as a series incandescent lamp used on constant current circuits and operate upon the occurrence of a break in the lamp circuit to complete the shunt circuit and thus maintain the remaining good lamps on the circuit in operation.

It has been proposed heretofore to use a thin lilm of insulating substance or fabric between the contact surfaces which would be broken when the potential reaches the proper point. It has also been proposed to build up a unit to be inserted between the opposing contact surfaces consisting of two metal blocks with an interposed lilm of insulation. These and other devices of the sort which have been proposed heretofore bring the contact surfaces themselves or the live portions of the circuit adj accnt to the film so close together that there is often a considerable leakage of current between them. due to moisture forming a path between the con tacts.

The principal object of the present invention is to provide a member to be located between the faces of the opposing contacts which will insulate them lrom each other by a very thin layer or coating of insulation and at the same time mechanically hold them a considerable distance apart so that the possibility of leakage between lhe'coutacts will be reduced to a minimunn ln carrying out the invention I employ a 1 conducting substance coated with an insulating illll'l't. In this way as soon as the insulationis broken down the circuit is completed between the opposing contacts through the intervening, conducting substance, while before the circuitis completed the opposing contacts are electrically insulated from each ducting substance.

other only by the thin coatings on the con- On the other hand the opposing contacts are maintained at all times a considerable distance apart.

The character of my invention will be more fully understood u )011 reference to the follow-- ing description talien in connection with the accompanying drawing and the noy el features oi. the invention will be specifically pointed out in the appended claims.

In the accompanying drawing, Figure 1 is a side elevation partly insection of a series incandescent lamp to which my improved cut-outhas been applied; Fig. 2 is a top plan View of the same; Fig. 3 is a section of the insulated n'iember which is interposed between the opposing contacts; and Fig. 4 is a sectional cievation of a modilied form of socket for an incandescent lampito which the cutout may be applied.

Referring in detail to the drawing, 10 designates the member which is interposed between the contacts which are to be electrically connectcd upon the occurrence of a rupture in the circuit of the translating device. Each of these members, of which there may be one or more consists of some conducting substance covered with a thin layer of insulation; preferably I employ a short piece of copper wire 1] covered with an insulating coating 12 of enamel, lacquer or other suitable insulating material. In the form of lamp illustrated in Figs. 1 and 2, these members are interposed between the shunt contacts 13, 13*, which are placed in shunt to the lamp terminals, 13 taking the form of a metal tongue screwed fast to one terminal and lying over the other contact 13" which is in the form of a glass ring connected to the other terminal in such a manner that when one or more of the members 10 are slipped under the tongue a shunt to the lamp iilament is completed. "lhese contacts 13 and 13, due to the resilience of the material, tend to come into engagement so that whenever the insulation 12 breaks down, a circuit is completed between them through the conductive portion 11 of said member.

The lamp shown is a well known form of construction and need not be described in detail.

In Fig. 4 the members 10 are shown interposed between two resilient strips 14 and 14 connected to the terminals of the lamp socket and adapted to be inserted between two spring strips 15, 15 mounted on a switchboard or base 16 on which the circuit connections are made. With this construction the lamp and its socket may be withdrawn from the switchboard and the menu bers 10 put in place between the strips 14., le I and the whole then inserted in the switchboard. So long as the lamp operates satisfactorily the insulation 12 remains inopposing; contacts, movable toward each other when unrestrained, of interposed means for insulating said contac from each other with a thin layer of insulatum and inc-- chanically maintaining them aparta distance greater than the thickness of the insulotion.

2. in an automatic cut-out for electric translating devices, the combination with opposing, contacts movable toward each other when unrestrained, of an intervening;

conductor insulated from each of said contacts.

3 In an automatic cut-out for electric translating devices, the combination With opposing contacts, of an intervening conductor insulated from each of said contacts by an interposed film of insulation and normally holding them under strain.

4. In an automatic cut-out for electric translating devices, the combination with opposing;- contacts movable toward each other when unrestrained, oi an intervening coiuluctor insulated from each of said corrtacts by an interposed lilm of enamel.

5. In an ai'ltoinatic cut-out for electric translating devices, the combination with op 'iosing contacts movable toward each other When unrestrained, of an intervening conductor coated with a lihn of insulation so as to maintain said contacts mechanically a considerable distance apart and electrically insulate them [rom each other by a thin layer of insulation.

(i. The combination with an electric translating device, of opposing contacts in a shunt around the same, and an intervening conductor insulated from each of said contacts.

in Witness whereof l have hereunto set in y hand this 225d day oi? June, W05.

Jill- N 'l. MiiltSllAlili. ll itnesses:

JOHN E. lk'lITOHELL, Jr., GEO. V. Downer. 

